(116f) A Novel Approach to Cross-Linking Gelatin Matrices

The goal of this research was the optimization of a cross-linking strategy that would yield high compressive strength, as well as increased durability of gelatin-based three dimensional porous structures, useful in tissue regeneration. A novel approach of using a dual cross-linking series of Dimethyl Suberimidate (DMS) and N-Hydroxysuccinimide (NHS) to affect two different functional groups present in gelatin was chosen for this purpose. The hypothesis is that the first cross-linker (DMS) forms an unstable ester with gelatin. Subsequent addition of a second cross-linker (NHS) would react with the formed ester and stabilize it. Experiments performed showed support for the proposed hypothesis, as it was noted that the strength and durability of the structures increased when both the cross-linkers were used. Optimization was carried out through a factorial design of experiments and compression tested in hydrated conditions. A six-parameter regression model was developed from which surface plots were generated. Cross-linking density was assessed with Trinitrobenzenesulfonic acid labeling of primary amines. FTIR analysis was performed to identify cross-linking of both the functional groups. Work is currently being done to enhance the effectiveness of the secondary stabilizing reaction, most notably the use of N-Ethyl-N'-(3-dimethylaminopropyl) carbodiimide in place of NHS.